Colorimetric Detection Of Melamine Based On The Size Effect Of AuNPs

Content Provider	Indian Institute of Science (IISc)
Author	Paul, Ida Evangeline Rajeshwari, A. Prathna, T. C. Raichur, Ashok M. Chandrasekaran, N. Mukherjee, Amitava
Copyright Year	2015
Abstract	A simple colorimetric detection of melamine was studied using 15 nm (AuNPs-I), 30 nm (AuNPs-II), and 40 nm (AuNPs-III) citrate-capped gold nanoparticles (AuNPs). The AuNPs aggregated in aqueous solution in the presence of melamine, showing a visual color change from red to blue. This color change led to a shift in the absorption peak from 527 nm, 526 nm, and 525 nm to 638 nm, 626 nm, and 680 nm for AuNPs-I, AuNPs-II, and AuNPs-III, respectively. For all the three AuNPs, linearity was observed between the melamine concentration in aqueous solution and the absorbance ratios, A(638 527), A(626 525), and A(680 526), respectively. The limit of detection (LOD) for melamine for the AuNPs-II was found to be 2.37 x 10(-8) M (correlation coefficient R-2 = 0.9745), which showed better sensitivity as compared to the LOD of the AuNPs-I and AuNPs-III, which were 3.3 x 10(-8) M and 8.9 x 10(-8) M, respectively. The synthesis of AuNPs-II also involved a lower HAuCl4 concentration compared with the other two types of AuNPs, which may reduce the process cost. The AuNPs-II was selected to analyze melamine in pre-treated milk samples, and the recovery percentage was in the range of 91-106%. Thus, the efficient detection of melamine was possible using AuNPs-II for the on-site detection without the aid of expensive instruments.
File Format	PDF
Journal	PeerReviewed
Language	English
Publisher	ROYAL SOC CHEMISTRY
Publisher Date	2015-01-01
Access Restriction	Authorized
Subject Keyword	Materials Engineering (formerly Metallurgy)
Content Type	Text
Resource Type	Article